Zeolites are very effective materials for the purification and separation of gases
by adsorption. We review those properties of zeolites which determine their selectivity for different gases, especially the size and shape of the micropores and the exchangeable cations.
We recommend particular
models for describing equilibrium properties such as selectivity and enthalpy. After summarizing the principles of adsorption kinetics, we discuss and compare the theories used for mathematical models of transport properties
in zeolites. Finally, we review industrial gas separations by zeolites, especially gas drying, air separation, and hydrogen production.